Rotate to advance catheterization system

ABSTRACT

A system of rotate-to-advance medical devices including catheters, dilators, occluders, stents, suprapubic catheters and camera introducers configured with external screw threads and depending substantially on rotation for means of advancement and emplacement in mammalian genitourinary and gastrointestinal passages and organs.

This application is a continuation-in-part to U.S. Ser. No. 08/505,040filed Jan. 11, 1996, now U.S. Pat. No. 5,601,537 issued Feb. 11, 1997,and relates to and claims priority to pending applications Ser. No.08/585,040 filed Jan. 11, 1996, U.S. Pat. No. 60/012,276 filed Feb. 2,1996, and PCT/US96/09274 filed Jun. 6, 1996, all by thisinventor/applicant.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

This invention most generally relates to apparatus and methods ofcatheterization and related treatments of the genitourinary andgastrointestinal passages of mammals. More particularly, the inventionrelates to catheters, dilators, occluders, stents, suprapubic catheters,camera introducers and related medical devices subject to beingproximally propelled and directed for advancement and control inmammalian genitourinary and gastrointestinal passages.

2. Description of the Prior Art

In most mammals, mucous membranes line all those passages by which theinternal parts communicate with the exterior, and are continuous withthe skin at the various orifices of the surface of the body. They aresoft and velvety, and very vascular, and their surface is coated over bytheir secretion, mucus, which is of a tenacious consistence, and servesto protect them from the foreign substances introduced into the bodywith which they are brought in contact.

They are described as lining the two tracts--the genitourinary and thegastrointestinal; and all, or almost all, mucous membranes may beclassed as belonging to and continuous with the one or the other ofthese tracts. Catheterization of any of these similar bodily passagesmay at times be useful or necessary.

Urinary outlet problems most likely have been around for as long ashumans. History has the ancient Chinese using onion stalks to relievepeople of acute urinary retention. Literature refers to such problems asfar back as 206 B.C., more than 2000 years ago. Romans used catheters,first invented by Erasistratus, a Greek doctor in the third century B.C.Roman catheters were fine tubes made of bronze. The Roman gynecologistSoranus describes how catheters could be used to push stones out of theway and back into the cavity of the bladder, and thus restore urineflow. Excavations in Pompeii unearthed several bronze catheters. Theseinstruments were well constructed but relatively simple and showed thatdesigns changed little from the period 79 AD until 1700 A.D.

However, during the 17th and 18th centuries catheter construction becamemore complex with an intensified search for an appropriate substancethat would be at once flexible, non-irritating and functional. England,France, and the U.S.A. had individuals and companies deeply involvedwith urinary catheters during this period. Many variations were producedbut they all caused much stress on the patient when these rigid deviceswere pushed into the urethra. The first practical breakthrough was bythe French using gum elastic catheters--a catheter that would bendbetter in the urethral channel and not scour the mucosa so much in theprocess.

Charles Goodyear improved upon what the French produced when hesuccessfully vulcanized crude rubber. The problem of manufacturing aninstrument which was both sufficiently rigid to enable it to be pushedthrough the urethra into the bladder and yet flexible enough tonegotiate the path, had at last reached the point of practicality, notwithstanding its shortcomings. At that time, and still to this day, afunctional urethral catheter is defined as one that is flexible enoughto negotiate the bends and stable enough to push through the length ofthe urethral passage.

The French urologist J. J. Cazenave, with the hopes that his countrywould regain leadership in the catheter field, dedicated 25-30 years ofhis life improving the flexible durable catheter. This was in the late1800's and his catheter, made of decalcified ivory, was a dated devicebut shows the consistency of the state of the art wherein catheters arepushed into and negotiated along the urethral passage toward thebladder.

During the past 300 years or so, intensified development efforts werestimulated by professional pride, national pride and financial rewards.These efforts yielded many improvements, such as changes to size, curveshape, materials of construction, smoothness, lubricants, coatings,combinations of materials, physical properties, chemical properties andmore, yet all subscribed to the basic principle of externalpush-to-advance.

The catheters of the prior art are large and stiff, difficult anduncomfortable to administer, and uncomfortable to wear for extendedperiods. There is a degree of skill, tolerance and patience requiredthat takes much time, training and practice to learn. The difficulty,discomfort, risk of injury and infection, inhibition and inconvenienceof the methods and tools of the known art results in the deprivation formany patients of the freedom to work, play and travel as do unaffectedpeople.

The anatomy of the adult male urinary tract, as illustrated in FIG. 1,has a bladder 004 where urine is collected prior to exiting the body viathe urethra 006. The bladder 004 converges into the urethra 006 at amuscular exit called the bladder neck 005. Approximately the first oneinch of the urethra lies within the prostate 007, which is achestnut-sized gland. The next approximately half inch passes throughthe external sphincter 008, which is the muscular flow valve thatcontrols the release of urine. The remaining six inches of the urethralie in a spongy zone, exiting the body at the meatus 009.

The normal process of emptying the bladder can be interrupted by twocauses. One is bladder outlet obstruction and the other is failure ofthe nerves linking the bladder to the brain. The most frequent cause ofbladder outlet obstruction in males is enlargement of the prostate glandby hypertrophy or hyperplasia. In older males, it is not uncommon for aprogressive enlargement of the prostate to constrict the prostateurethra. This condition, known as benign prostatic hyperplasia (BPH),can cause a variety of obstructive symptoms, including urinaryhesitancy, straining to void, decreased size and force of the urinarystream and in extreme cases, complete urinary retention possibly leadingto renal failure.

The most common surgical intervention for BPH, transurethral resectionof the prostate, or TURP, has a lengthy recovery period of up to oneyear, and presents a high operative risk for complications such assexual dysfinction. Up to 10% of those subjected to such surgery areleft with mild to moderate stress incontinence. Approximately 400,000patients in the United States and approximately 500,000 patientsinternationally were diagnosed in 1994 with BPH or cancer-inducedbladder outlet obstructions that were sufficiently severe to warrantTURP or alternative surgery, according to industry sources.

Because of the high costs, medical risks and quality of life compromisesassociated with TURP, new technologies have begun to challenge TURP'sposition as the standard treatment for severe BPH. Recently, the U.S.Food and Drug Administration approved two drugs, tera zosinhydrochloride and rinasteride, to treat BPH. These drugs generally donot improve symptoms for six to nine months after treatment begins, andare not without side effects.

Urethral strictures are another cause of outlet obstruction, often dueto fibrous tissue growth resulting from reaction to catheters orcystoscopes or from injury, birth defects or disease, and are commonlytreated by urethral dilation, catheterization or surgery. Men withurethral strictures also experience a limited ability to urinate, whichmay cause extreme discomfort and, if left untreated may causecomplications that necessitate catheterization. Approximately 50,000patients in the United States were diagnosed with recurrent urethralstrictures in 1994, according to industry sources. The inventorestimates that approximately 75,000 additional patients were diagnosedinternationally.

Women suffer from urinary incontinence far more often than men and at anyounger age primarily because of the stress associated with pregnancyand childbirth, the shorter length of the female urethra, and theabsence of a prostate. The U.S. Department of Health and Human Services(HHS) estimates that the involuntary loss of urine affects approximately10 million Americans of which 8.5 million are women. Seven million ofthese women are non-institutionalized, or community-dwelling.

For women between the ages of 15 and 64, the prevalence of urinaryincontinence is estimated to range from 10 to 25 percent of thepopulation. For non-institutionalized persons over the age of 60, theprevalence of urinary incontinence ranges from 15 to 30 percent, withthe prevalence in women twice that of men.

The involuntary loss of urine can be caused by a variety of anatomicaland physiological factors. The type and cause of urinary incontinence isimportant to how the condition is treated and managed. The two broadcategories of urinary incontinence are urge and stress incontinence.Some people suffer from what is termed mixed incontinence or acombination of stress and urge incontinence.

Urge incontinence is the involuntary loss of urine associated with anabrupt and strong desire to void. In most cases, urge incontinence iscaused by involuntary detrusor (the smooth muscle in the wall of thebladder) contractions or over-activity. For many people, urgeincontinence can be satisfactorily managed with pharmaceuticals.

The more frequently occurring stress incontinence is the involuntaryloss of urine caused by movement or activity that increases abdominalpressure. The most common cause of stress incontinence is hypermobilityor significant displacement of the urethra and bladder neck duringexertion. A less frequent cause of stress incontinence is intrinsicurethral sphincter deficiency (ISD), a condition in which the sphincteris unable to generate enough resistance to retain urine in the bladder.

Females, and males with no benign prostatic hyperplasia condition, mightalso have the inability to empty their bladder because of the nerveslinking the bladder to the brain. This condition is known as neuropathicbladder, may occur in a wide variety of conditions which include spinabifida, multiple sclerosis, spinal injury, slipped disc and diabetes.When these and other problems prevent the bladder from effectivelycontrolling urine there are a number of treatment options. They arecatheters, dilators, occluders, and stents.

Indwelling Foley-type Catheters

During continuous catheterization an indwelling catheter is retained inthe bladder by a water filled balloon. It drains urine continuously fromthe bladder via a connecting tube into a bag which is attached to theleg or bed. The bag has a tap so that the urine can be emptied atintervals. The catheter is usually inserted by a doctor or nurse andchanged about every four to six weeks. But difficulty in placement hasalways been inherent in this design. This is due to the traditional"push to advance" technology which necessitates a relatively stiff,thick-walled catheter to traverse the delicate mucosal lined urethra.

Often the French (unit of measurement) size of the catheter is dictatedby the need for stiffness to insert rather than the lumen size to passurine. A 14 French or smaller Foley is rarely used because catheters ofthis size lack the column strength needed to push the full length of theurethra into the bladder. The larger French Foley catheters are painfulto place, uncomfortable when indwelling, and require a highly skilledcare provider to insert.

Intermittent Catheters

During intermittent catheterization a simple catheter made of plastic,rubber, or metal is inserted by the patient or a helper for just longenough to empty the bladder completely, which is typically about oneminute. These tubes are usually smaller in diameter and stiffer than anindwelling catheter of the same size. This stiffness can makecatheterization difficult in men because the urethra is long and has anacute bend within the prostate. When the external sphincter is reachedthe sphincter muscle will contract making passage difficult. Mostpatients learn to catheterize themselves and thereby gain a large degreeof independence. This process is repeated about every 3-4 hours duringthe day and occasionally as needed at night.

Intermittent catheterization is mainly used by people who areincontinent due to neuropathic bladder. Intermittent catheterization mayalso be utilized by people who cannot empty the bladder because thebladder muscle is weak and does not contract properly. In some patients,an alternate apparatus and method used to maintain long term drainage ofthe bladder is the use of a suprapubic tube.

Suprapubic Catheters

Suprapubic catheterization of the bladder is performed viatransabdominal puncture which enters the body above the pubic arch andis directed into the bladder using ultrasound or fluoroscopy to guidethe trocar introducer and suprapubic catheter. The needle introducer isthen removed when proper catheter placement within the bladder isconfirmed, leaving the drainage catheter in place.

Long term drainage may require the fixation of the catheter at the skinusing standard adhesive based interface components to address mechanicalfixation, inflection control, and skin compatibility. The distal end ofthe catheter is commonly contained within the bladder by inflatedballoon, winged-shaped tip configurations which expand within thebladder, or pre-shaped curved catheter tips which curl to their originalJ-shape when stiffening wire is removed from the catheter lumen.

A problem with this form of distal end emplacement through the bladderwall is that it is only unidirectional; that is, it only resists theinadvertent pulling out of the tip of the catheter from the wall of thebladder, while allowing the catheter to freely pass further into thebladder, and back out up to the point of the containment structure. Thiscontinuing catheter motion in and out of the bladder puncture site mayirritate tissue and cause infection or other difficulty at thebladder-catheter interface. Urine is especially irritating to most partsof the human body that are outside the urinary tract.

Dilators

Dilation is accomplished by pushing successively larger urethraldilation tubes through the urethra to increase the size of the lumen, aprocedure which is painful and traumatic to the patient. Surgicaltreatment of strictures involves surgical risks as well ascomplications, including infection, bleeding and restenosis, whichrequires further treatment.

With the exception of balloon catheters, the current art of dilators hasalso changed little over the passage of time. A shaft with an increasingtaper, bulbous structure, or enlarged end is pushed from without thepassage to advance the tool through the restricted passage, thus forcingby longitudinally-applied pressure the lateral expansion of the passagewalls. This push-to-advance method necessitates a stiff shaft which hasall the same liabilities as traditional catheters. Catheters inherentlyprovide a degree of this dilatorial function to the extent that thepassage is opened sufficiently to accommodate the catheter.

Occluders

Occluders are used in some cases to control incontinence. Occluders ofthe prior art are constructed and applied with the same push-to-advanceconcept as catheters and dilators described above, with the sameliabilities. The basic occluder is a bulb or plug on a shaft which isinserted within a passageway to stop or prevent the normal flow ofmaterials through the passageway, or driven all the way into thebladder, for example, and allowed to seat as a plug at the neck of theurethra to prevent the flow of urine from the bladder.

Stents

A stent is a tubular metallic mesh device that is implanted to open andsupport a stricture to allow for urine flow. The stent body is between3.5 cm and 6.5 cm in length depending on the anatomy, and is expandableby design to anchor in place. The stent being a mesh has openings thatallow the tissue to grow through the wall making removal difficult andcausing encrustation that reduces urine flow.

Intraurethral Valved Catheters

An intraurethral valved catheter is a device that is implanted tocontrol the flow of urine with an integral valve that is remotelyactuated. Since the entire catheter length is within the urethra, thechance for external infection is reduced. The anchoring mechanism ofcurrent designs is accomplished with balloons, or "petal like"projections from the catheter. Both designs are complicated to installand difficult to remove, and if the valve fails, leaves the patient in apainful and dangerous situation.

Patents in the Prior Art

There has been patent activity in the prior art indicatingdissatisfaction with the push-to-advance methodology. Catheters havebeen adorned with a wide assortment of spiral and threaded featuresdescribed as intended to ease the trauma and pain of what clearlyremained a push-in device. Alvord's U.S. Pat. No. 207,932 (US), Peyret'sU.S. Pat. No. 564,832 (French), Hayes' U.S. Pat. No. 1,644,919 (US), andJacoby's U.S. Pat. No. 1,888,349 (US) are representative of these. Inall cases, these disclosures fail to recognize that the basic pushtechnique is fundamentally flawed and should be abandoned, and fail toresolve the critical features of structure necessary for rotationaladvancement as a substitute for the push method.

Other art reveals the use of spiral features for different purposes. Forexample, Spinosa's U.S. Pat. No. 3,815,608 (US), discloses a catheterwith a thread designed to hold the urethral wall away from the shaft toallow urine to flow around the outside of the catheter. Thesedisclosures likewise reveal a reliance on push-in methods or anassumption that such structures can be pulled out without regard to thespiral features, again failing to recognize rotation as a viablesubstitute for push, and failing to resolve the critical features ofstructure necessary for effective rotational advancement.

As a further indication of the failure of prior art similar to the aboveinventions to provide effective improvements to push-in methods, thereis no apparent indication among the products commercially available, orin the medical practices known to the applicant, that any of thesespirally ornamented devices were ever found to be viable.

Gastrointestinal Endoscopes

The current device used for inspection and treatment of the GI(gastrointestinal) tract is a flexible Endoscope. This device takes ahigh level of skill to use, is difficult to maneuver and can be verypainful for the patient, due to the basic push-to-advance design thathas not changed since the device was invented in the early 1960s. Thedistal tip of the endoscope has the following parts:

1. a channel opening for suction and passage of accessories,

2. the light guide lens to distribute light from the fiberoptic bundleto illuminate the visual field,

3. the objective lens to focus an image of the mucosa onto the face ofthe image bundle and transmit it back to the eye piece,

4. an air/water jet, which supplies air to inflate the organ beingobserved, and water to clean off the image lens.

The Bending Section is the distal end of the tube, ranging from approx.8-15 cm long, which can articulate to steer the scope as it is pushedinward and is controlled by a cable mechanism that is connected tocontrol knobs on the proximal handle.

The Insertion Tube, which makes up the rest of the 60-150 cm length, isnot capable of controlled deflection. It has a tailored bendingflexibility and torque transmission which is of major importance inendoscope design. Most instruments have two-stage bending stiffness,i.e., the distal portion of the insertion tube is more flexible than theproximal portion. The Flexibility of each portion of the insertion tuberequires extensive clinical testing to ensure that the endoscope handleseasily and produces a minimum of patient discomfort.

The colon is a tubular organ which runs from the cecum in the rightlower quadrant to the rectum. It is widest in the cecum and ascendingcolon and gradually narrows as one approaches the rectum. The colon isdivided into the following sections:

a. the cecum; the ascending colon, which runs cephalad (towards thehead) from the cecum to the hepatic flexure;

b. the transverse colon, which runs from the hepatic flexure in theupper quadrant of the splenic flexure in the left upper quadrant;

c. the descending colon, which runs caudad(toward the feet) from thesplenic flexure to the left lower quadrant;

d. the sigmoid colon, which runs from the left lower quadrant to therectosigmoid junction; and

e. the rectum, which extends down to the anal canal.

The inner layer of circular muscle is present throughout the colon. Theouter longitudinal muscle in the wall of the colon is fused into threebands, the teniae coli. These bands start at the base of the appendixand run in the wall of the colon down to the rectum where they diffuseinto the muscular coat. The three teniae cause the colon to have atriangular appearance endoscopically; this is especially prominent inthe ascending and transverse colon. The haustra are outpouchings of thecolon, separated by folds. In the descending colon the endoscopicappearance is often tubular.

Most experienced colonoscopists use similar endoscopic techniques. Airis introduced to inflate the colon, but as little as possible to preventoverdistension. The pressure on the device is gentle to avoid stretchingthe colonic wall or mesentery (the connective tissue that holds thecolon like a fan) which can cause pain, a vagal episode, or aperforation. The lumen is kept in view at all times; little or none ofthe examination is performed blindly, because you are pushing a stiffinstrument.

A variety of in and out maneuvers are used to "accordian" the colon onthe colonoscope, keeping the colonoscope free of loops as possible. Inthe difficult colon, special maneuvers such as the creating of an alphaloop in the sigmoid colon are used to pass the sharply angulatedsigmoid/descending colon junction. This maneuver may requirefluoroscopic guidance and training in the technique.

The colonoscope is advanced to the cecum under direct vision. Thedetailed examination of the mucosa is usually performed as thecolonoscope is slowly removed from the cecum.

To inspect the whole length of the large intestine requires a highlyskilled practitioner, which makes the procedure costly. Even still theprocedure can be very painful for the patient, making sedationnecessary. This is due to the inherent deficiencies in the"push-to-advance" design.

In summary, there are problems in making present push-in catheters,dilators, and occluders stiff enough for penetration and flexible enoughto make the turns without undue risk of trauma to the wall of thepassageway when being pushed in; and once installed, comfortable enoughto wear for an extended period. The problems with stent encrustation andremoval are well known. Self-administration is inhibited by all of theshort-comings of the prior art. Further injury, infection and discomfortcan result from unskilled or improper technique. The problems withcolonoscopy have been previously described.

The long history of push-in catheters/dilators and occluders hasgradually crystallized into an industry wide, self-perpetuating,fundamental assumption that catheters are to be mainly pushed throughbodily passageways, albeit with some rotational easing. This "fact" isso widely perpetuated and pervasive in the commercially availableproducts and medical practices as to have stifled original thinking inthis art. This, in spite of it's well-recorded short comings of pain,trauma, risk of rupture, and failed, aborted or incomplete proceduresand need for skilled practitioners and special equipment for monitoringand safeguarding against the inherent problems.

SUMMARY OF THE INVENTION

For the purposes of this disclosure, including the appended claims, theterms "distal", "distally", and "distal end", as they relate to thedevices and methods described herein, refer to the end of the devicefurther from or in the direction away from a practitioner who might beapplying the device or method to the subject. Stated otherwise, theterms refer to the end of the device closer to or in the directiontowards the subject's interior.

The terms "proximal", "proximally", and "proximal end", as they relateto the devices and methods described herein, refer to the end of thedevice closer to or in the direction towards the practitioner who mightbe applying the device or method, rather than the subject.

Objects of the invention include providing and employing screw-basedmeans for rotational advancement and anchoring of catheters, probes,occluders, stents, and dilators into genitourinary and gastrointestinalpassageways such as the urethra, ureter, esophagus and fallopian tube,and for the emplacement of suprapubic catheters for draininggenitourinary organs such as the bladder, whereby the subject device isapplied through a natural body orifice or surgically created opening andis drawn through the passage by the longitudinal pull of a helix on thewalls of the passage or organ as the device is rotated. This technologyis a radical departure from the 4000 year old traditional "push toadvance" methodology previously discussed.

Indwelling and Intermittent Catheters

Flexible, thin wall indwelling and intermittent catheters and relateddevices and delivery stylets, made possible by this form of emplacement,are less traumatic and easier for the medical practitioner or patient touse. The catheter of the invention eliminates the problems ofconventional devices by using helix or rotational technology thatprovides controlled insertion and flexibility to negotiate the urethra.The helix design accomplishes a pre-dilatation of the passageway at asteady rate that relaxes the sphincter and lessens or prevents spasm.Once placed, the device is anchored by the radial displacement and closepitch of the helix, preventing longitudinal migration due to bodymovement or fluid flow.

In another embodiment, the helix is located on the shaft under aFoley-type balloon and disappears when the balloon is inflated. Theflexible reinforced shaft need be only about half the wall thickness ofconventional Foley Catheters, which means a smaller OD catheter can beused. The helix advances the shaft and dilates the urethra as thecatheter is inserted. Once the bladder is reached the balloon isinflated with sterile water, the helix is engulfed by the balloon. Theprocess is then reversed to remove the catheter. This technology fostersreduced costs for patent care, improved clinical outcomes and enhancedpatient quality of life.

Continence Catheter with Valve

The continence catheter of the invention, indicated for bladder outletobstructions, is intended for BPH patients who are not able to, orchoose not to undergo TURP. This embodiment of the invention allows theurethra in the area of the prostate to remain open. At the proximal(external end) of this catheter there may be a flow valve which can bedepressed or otherwise opened to empty the bladder. The catheter may beproduced as a sterile, single-use, disposable item that can be used onceand replaced as needed.

The same embodiment of the catheter of the invention provides a femaleStress UI sufferer with lifestyle benefits that greatly outperformabsorbent products intended to manage this condition.

The patient simply inserts the catheter into the urethral opening androtates the shaft to advance the catheter into the bladder. This can bedone in the morning in the convenience of home. When the user needs tourinate, the valve end of the flexible shaft may be exposed through theclothing and the valve opened to empty the bladder. Since the device isnot removed and reinserted after each voiding the risk of infection isreduced. At the end of the day the catheter is easily removed anddisposed.

Intraurethral Valved Catheter

The male or female intraurethral valved catheter of the invention isindicated for bladder control. This embodiment of the invention allowsthe flow of urine to be controlled by a valve mechanism that is withinthe catheter. This valve may be actuated directly by insertion of a toolsuch as a stylet, or remotely by using a magnetic field device.

The intraurethral device reduces the potential for infection byeliminating the external tubing which can be an entry path for bacterialcontamination. These catheters are typically 3.5 to 6.5 centimeters inlength, depending on the anatomy, and have the helical element of theinvention on the outer diameter of the body. The thread height of thehelix may vary over it's length, as an aid to the advancement andretention characteristics of the device. The sidewall of the cathetermay be reinforced to resist collapsing due to contraction pressure. Thiscatheter may be inserted in the urethra under fluoroscopy, using adetachable flexible stylet which keys into the proximal end of thecatheter in a non-rotational fitment, and may be inserted in anoutpatient procedure using topical anesthesia.

Stents

The stent of the invention, indicated for bladder outlet obstructions,keeps the urethra open in the area of the stricture. The stent body maybe between 3.5 cm and 6.5 cm in length depending on the anatomy, and hasa helical element on the outer diameter of the body to advance andretain the stent. The sidewall of the stent may have a reinforcementmeans to prevent collapsing due to prostate pressure. The stent can beinserted in the urethra under fluoroscopy, using a detachable flexiblestylet which keys into the proximal end of the stent body, and may beinserted in an outpatient procedure using topical anesthesia.

The stents of the invention are not susceptible to being incorporated bythe urethral mucosa in a manner preventing rotation, thereby permittinga lengthy period of emplacement and subsequent removal by the samerotational technique. The stent may also have a sufficiently largeinternal diameter, or lumen, to permit cystoscopies, thereby allowingexamination of the bladder without removing the stent.

Dilators and Occluders

Helically-adapted dilators and occluders of the invention are likewiserotatingly advanced and retracted; the helical element performing adilatory finction to some degree. Dilators of respectively largerdiameters may be used to achieve a gradually more pronounced effect. Therotational advancement means may be combined with the push-to-advancemethodology in any of these devices. In a dilator, for example, ahelically equipped leader shaft extending distally of the bulbousportion of the device rotatingly advances the device up to the pointthat the helix passes out of the interior end of the passage, theremainder of the leader shaft then providing a guide wire that leads thebulb through the remainder of the passageway when the dilator is pushedfrom the proximal end.

Suprapubic Catheters

The adaptation of the invention to suprapubic catheters used in aclassic transabdominal puncture for the drainage of the bladder or othergenitourinary organs, permits the helix on the distal end of thecatheter to be emplaced in the wall of the organ far enough so that thehelical vane extends from both sides of the organ wall, so that thelongitudinal sliding motion of the catheter into and out of the organ isinhibited by the helical vane. This reduces a source of irritation andassociated complications at the organ wall entry point.

The helically-adapted suprapubic catheter may be placed in the organusing ultrasound or fluoroscopy to visualize placement, by rotatinglyadvancing the catheter over a guidewire leading to the organ; theguidewire having been installed through a tubular access created byusing a cannula and trocar to reach the organ, the trocar and thecannula having been successively removed.

General Construction

Any embodiment of the invention may be radiopaque, or have radiopaquefeatures, markers or other components, permitting the use of fluoroscopyto monitor emplacement or removal of the device, or even the rotationalorientation and rotational movement.

The thread element may be solid, hollow, or fluid filled. It may taperin height at various locations to optimize advancement and anchoring.Embodiments or elements of the invention may be fabricated, molded,wound, extruded or otherwise constructed of non-toxic, non-corrosivematerials or combinations of materials that are otherwise tolerant ofbodily fluids and durable when implanted in vivo. Such materials mayinclude but are not limited to polyurethane, medical grade stainlesssteel, silicone, bicarbon, polytetrafluoroethylene, tantalum, titanium,or nickel-titanium alloy. Conversely, materials may be specificallychosen to be bioabsorable so as to obviate the need for removal.

The devices of the invention may be enhanced with one or a combinationof the following coatings: water based hydrophilic, antibacterialcoatings such as nitrofurazone, bateriostatic coatings such as silver,or other mediations to further enhance their clinical performance.

Camera Introducer

The threaded camera introducer system, briefly stated, presents a novelmeans for the introduction of sensors and other implements into andthrough the full length of the colon. The flndarnental structure of theintroducer, consistent with the rotate-to-advance structure andmethodology of the invention, is a large, soft, flexible worm-liketubular device with a helix of soft, pliant threads which translaterotational force at the proximal end to a pulling action on the colonwall.

The hollow core or central lumen connects the distal and proximal endsof the tube. A camera head or other visual sensor can be introduced intothe device and arranged to "see" forward from the center of the bulboustip on the distal end. Light bundles or wires connected to the camerapass through the central lumen and out the proximal end of the device toan appropriate control and viewing apparatus.

The distal end of the device is gently urged into the rectumsufficiently far to engage the helix. The device is rotated from justoutside the point of entry, to slowly advance into and through theentire length of the colon to the cecum. The helical threads pulling thedevice gently along the interior colon wall; the flexibility of thedevice allowing it to easily negotiate the major turns of the colon. Thelarger threads at the distal end provide the greatest grip or pull, thesmaller threads closer to the proximal end contributing a lesser degreeof grip or pull. The device is removed using the same method in reverse.

As illustrated in the figures, the light bundles or cables may beencased in a flexible torque tube or assembly which provides orcontributes to the torsional strength necessary to rotatingly advanceand withdrawn the device.

The interior wall of the main tubular device or introducer, may beconfigured to contain the torque tube or vertebra in a non-rotationalmanner, such that torque applied at any place on the exterior wall ofthe introducer is transmitted to the torque tube and hence over the fulllength of the device.

Various embodiments and enhancements are possible, all within the scopeof the invention:

1. The helical thread or spiral extending the length of the device maybe used for auxiliary purposes, including to:

a) Carry fluids into the colon/passage,

b) Provide vacuum to the passage way itself or vacuum within the deviceto facilitate the advancement of the camera or endoscope into thedevice,

c) Convey light bundles or electrical wires for specific purposes,andlor

d) Provide depth markers to assist the practitioner in determining thegeneral position of the device within the body.

2. The spiral may also be inflated with a fluid during entry to obtainfull thread form and rotationally grip or fix the catheter to the cameraelement, and deflated to permit non-rotational removal by pulling thedevice through the colon.

3. The video screen or the image on the screen as seen through therotating camera introducer as it advances, may be electronicallyprocessed to hold the image in a non-rotating, stationary manner for thebenefit of the person administering the procedure.

4. The distal portion of the device may be relatively more flexible toenhance trackability along the path of the colon/passageway.

5. The device may have sufficient torque transmission capability fromthe proximal to the distal end so the distal portion of the device canbe thus rotated at full length in the colon without interior support.

6. The distal tip or zone may have a sufficient thread height to gripthe colon wall and provide the primary "pulling power" to advance thedevice into the body and negotiate the turns, while the somewhat lowerthread height along the balance of the device is adequate to supportrotational advancement without drag and avoid bunching or gathering thecolon wall.

7. There are at least three methods of containing and controlling this160 cm long instrument to ensure it remains within the operating field:

a) A dispensing device as shown in FIG. 34,

b) A straight tubular component, or

c) Held by an assistant.

8. Material of construction:

a) The main body may be produced from polyvinylchloride plastic and maybe reinforced with wire or fabric.

b) The helix may be made of PVC and may be reinforced with wire orotherwise.

c) A distal end window may be a flat, optically clear plastic lens madefrom PVC, polycarbonate, or acrylic plastic.

9. Alternative Uses:

a) Variations on the introducer device within the scope of the inventioninclude full length tubes, or short sections analogous to urethralstents, being emplaced in the colon by the rotational structures andtechniques of the invention for temporary purposes such as to aid in therepair of a damaged colon or a related abdominal injury or condition, byproviding a supplemental lining and/or form to the colon or to a sectionof the colon.

10. Camera with torque control umbilicus:

a) The camera body which houses both the camera and the light sourcesmay be made of stainless steel or molded with a dimensionally stableplastic such as polycarbonate.

b) The vertebrae which makes up the torque control umbilicus may be madeof a high strength thermoplastic or a metal such as stainless steel orberyllium copper.

By means of the invention, the entire colon can be examined without theneed for a conventional colonoscope or endoscope, and without theattendant expertise, pain, medication, post procedure recovery time, andcost. The means and method of the invention require less training andhave far greater likelihood of reaching the cecum, (far end of thecolon), than conventional tools and procedures. Other body cavities andpassageways may be similarly examined.

The camera introducer catheter can be used in four different modes:

1. As an INTRODUCER, it includes the following characteristics andbenefits:

a) Conveys a camera assembly along the entire colon to screen patientsfor polyps, lesions, cancer sights and other maladies.

b) The entire colon can be examined without the need for a conventionalcolonoscope/endoscope.

c) A total examination of the colon can be successfully performed withsignificantly less manipulation technique, pain, medication and postprocedure recovery time.

d) Requires less training and has greater success in reaching the cecum.

e) As a single-use disposable device, allowing the expensive camera withits torque controlled umbilicus to be used repeatedly without danger ofsequential infections.

f) Procedure is less expensive when compared to the cost of cleaning andrepairing the conventional endoscopes and amortizing the cost of today'scostly video processing unit.

g) The procedure can be successfully performed by less specialized, lessexpensive individuals.

h) The INTRODUCER is supplied sterilized and ready for use.

2. As a more CONVENTIONAL STYLE ENDOSCOPE:

By adapting a conventional endoscope to the structure and method of theinvention, the benefits of the invention are coupled with the followingconventional functions:

a) Tip articulation.

b) Air & water delivery.

c) Suction of fluids.

d) Illumination of passages.

e) Imaging capability.

f) Drug delivery.

g) Accessories.

3. As a HYBRID CATHETER having some of the functions and features of themore CONVENTIONAL ENDOSCOPE and/or the INTRODUCER style built into thedevice for procedure-specific applications. Also, it could be used inconjunction with or independent of conventional endoscopic devices andaccessories.

4. As a TRANSPORTER or introducer to deliver a conventional endoscope toany location of the colon or other passageway. This may occur by:

a) Providing a fluid tight envelope for the endoscope.

b) Providing a means for the endoscope to exit the distal end of theINTRODUCER to perform diagnostic/therapeutic procedures normally donewith the endoscope.

Still other objects and advantages of the present invention will becomereadily apparent to those skilled in this art from the followingdetailed description, wherein I have shown and described preferred andother embodiments of the invention, simply by way of illustration of thebest mode contemplated by me on carrying out my invention. As will berealized, the invention is capable of other and different embodiments,and its several details are capable of modifications in various obviousrespects, all without departing from the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of the lower abdominal anatomy of a malesubject, with the threaded portion of the catheter of FIG. 2 extendinginto the bladder.

FIG. 2 is a perspective view of a threaded catheter for a male.

FIG. 3 is a cross sectional view of the threaded portion of the catheterof FIG. 2.

FIG. 4 is a illustration of the threaded end of the catheter of FIG. 1engaged in the urethra.

FIG. 5 is a perspective view of a threaded catheter for a female.

FIG. 6 is a cross sectional view of the threaded portion of the catheterof FIG. 5.

FIG. 7 is a perspective view of a threaded catheter and flexible shaftstylet with which it is installed.

FIG. 8 is a cross section of the tip of the catheter of FIG. 7, showingthe non-rotational fitment that receives the tip of the stylet of FIG.7.

FIG. 9 is a perspective view of the tip of the stylet of FIG. 7 that isinsertable into the fitment of FIG. 8.

FIG. 10 is a diagrammatic longitudinal cross section view of a threadedballoon catheter showing the thread element inside the inflated balloon,with lumens shown as dashed lines.

FIG. 11 is a cross section view of the shaft of the catheter of FIG. 10,showing the central drain lumen and the smaller inflation lumen.

FIG. 12 is a longitudinal cross section view of the distal end of thecatheter of FIG. 10, showing the balloon contracted around the helicalelement.

FIG. 13 is a side elevation of a threaded dilator.

FIG. 14 is a side elevation of a threaded occluder.

FIG. 15 is a side elevation of another variation of a threaded occluder.

FIG. 16 is a perspective view of a threaded stent, dashed lines showingan internal sidewall reinforcement member and a bushing with a hexagondrive socket.

FIG. 17 is a cross section view of the stent of FIG. 16.

FIG. 18 is a proximal end view of the stent of FIG. 16, with the hexagondrive socket visible at the center.

FIG. 19 is a perspective view of a stylet with a grip on it's proximalend and a hexagon drive tip on it's distal end.

FIG. 20 is a perspective view of the hexagon drive tip of the stylet ofFIG. 19.

FIG. 21 is a perspective view of a stent-follower with a helical elementat it's distal end.

FIG. 22 is a cross section closeup view of the distal end of thestent-follower of FIG. 21, showing the hidden portion of the bushingwith it's hexagonal drive aperture in dashed lines.

FIG. 23 is a cross section view of a intraurethral catheter with flowcontrol, showing the coiled wall reinforcement member acting as a springon the ball of the check valve.

FIG. 24 is a closeup perspective view of a stylet tip for operating thecheck valve of the intraurethral catheter of FIG. 23.

FIG. 25 is a diagrammatic illustration of a suprapubic catheter emplacedthrough the abdomen with the distal end anchored by it's helical threadin the bladder wall.

FIG. 26 is a partial side perspective view of the helical thread of thesuprapubic catheter of FIG. 25, anchored by it's helical thread in ahole in the bladder wall.

FIG. 27 is a partial front perspective of the suprapubic catheter ofFIGS. 25 and 26 anchored in a hole in the bladder wall; the hole beingstretched and deformed to fit tightly about the tube and thread of thecatheter.

FIG. 28 is a diagrammatic view of a trocar, cannula and guide wire, usedto install the suprapubic catheter of FIG. 25.

FIG. 29 is a distal end view of the suprapubic catheter of FIG. 21,showing rotational orientation markers.

FIG. 30 is a front perspective diagram of a threaded camera introducercatheter advanced into the transverse colon area.

FIG. 31A is a partial front-side perspective of the distal end of thecatheter of FIG. 30, showing the larger thread height of the thread inthe distal area of the catheter's length.

FIG. 31B is a partial side view of the mid section of the catheter ofFIG. 30, showing the reduced thread height of the thread in other thanthe distal area of the catheter's length.

FIG. 32 is a perspective view of a camera assembly with a video cameraor visual sensor head attached to a flexible torque tube or assemblywithin which run electrical cables and/or light bundles.

FIG. 33 is a partial cross section view of the distal end of thepreferred embodiment of FIG. 1, with the camera assembly of FIG. 2installed as it would be used, with textual information relating to theconstruction and use of the device.

FIG. 34 is a rotating container and dispensing device by which thecatheter of FIG. 30 may be managed and administered during it'sapplication to a patient.

DESCRIPTION OF THE PREFERRED EMBODIMENT

To those skilled in the art, the invention admits of many variations andappellations in apparatus and methodology. By way of example, there isprovided in accordance with the present invention, a rotate-to-advancestructure and methodology applicable to a range of medical devices thathave here-to-fore relied entirely or substantially on a push-to-advancetechnique for penetration of bodily passages. Such devices includecatheters, dilators, and occluders for mammalian genitourinary orgastrointestinal passages such as the urethra or ureter for the usualpurposes associated with such devices where no incising or rupture ofpassage walls or membranes is intended.

CATHETERS:

Referring now to FIGS. 1, 2 and 3, threaded catheter 101 for males ismade up of tube 102 with external thread 103, attachable to flow controldevice 104. Tube 102 is extruded from polyurethane material, has aninside diameter of 0.06 inches, an outside diameter 103d of 0.125inches, and is approximately 13 inches long. The durometer as measuredon the smooth, outside wall of the tube is 85 Shore A. Distal end 105 isclosed off, with it's tip rounded to a uniform radius of about 0.06inches. Proximal end 106 of tube 102 is simply cut off square andattached to flow control device 104. Tube 102 is sufficiently strongsuch that when the majority of its length is contained within theurethra, it will withstand and transmit torque as applied by fingerforce at the lower end external of the urethra, to the thread.

A useful alternative embodiment of catheter 101 incorporates the recitedexternal thread 103 for rotational advancement, but provides for thecentral lumen to connect to or terminate in a straight-through oraxially aligned drainage port at the distal tip of the catheter, similarto the most basic conventional catheters. This is likewise useful fordrainage and also enables the insertion or passage of guide wires orother devices where specific procedures require it.

Referring to FIGS. 2 and 3, external thread 103 is formed from a stripof polyurethane material with a rectangular cross section of width 103a,0.05 inches, and height 103b, 0.032 inches, and continuously attachedover it's length to tube 102 starting 0.2 inches from distal end 105 andextending four complete turns around tube 102 in a clockwise directiontowards proximal end 106 at a uniform pitch 103c of 0.25 inches,resulting in a four-turn thread or helix about one inch long.

It is readily apparent from the dimensions of FIGS. 2 and 3 that thethread height 103b of catheter 101 is greater than twenty percent (20%)of the 103d thread diameter. This relative height is necessary to expandand penetrate the longitudinal folds of the urethra to a sufficientdepth to achieve a useful grip by the thread.

The diameter of the helix formed by thread 103 of catheter 101 isreferred to as thread diameter 103d, and is equal to two thread heights103b plus the outside diameter 102d of catheter tube 102, or in thiscase 2 times 0.032 inches plus 0.125 inches or approximately 0.19inches. The circumference C of the helix formed by thread 30 iscalculated as π (pi) times thread diameter 103d, or in this case 3.14times 0.19 or approximately 0.6 inches.

    C=π·103d

The ratio R of thread pitch 103c, 0.25 inches, to the circumference ofthread diameter 103d, at 0.6 inches, is much less than 1 to 1, therebyimproving the leverage of the screw thread for converting rotation intolongitudinal pulling power as compared to ratios larger than 1/1.

    R=103c/C

The shoulders of thread 103 have a radius of 0.015 inches. In smallquantities, thread 103 may be attached to tube 102 by wickingtetrahydrofuran (THF) solvent under the thread using a fine hollow tube.Catheter 101 may be molded in large quantities with thread 103 being anintegral part of the molded structure.

Referring to FIG. 4, two drainage ports 107, connecting to lumen 108,are oval in shape, the major axis of the oval being parallel with theaxis of tube 102 and about 1.5 times the minor axis, which is aboutequal to the diameter of the lumen. The two ports are configured 180degrees apart radially, and spaced longitudinally to fit between theturns of thread 103.

Both ends of thread 103 are tapered from zero to full height in one-halfturn of the helix, to facilitate gentle, gradual displacement of urethrawall 002 by thread 103 when catheter 101 is rotated clockwise foradvancement into the urethra and counterclockwise for retraction. Thedifference between thread width 103b and pitch 103c shown in FIG. 3 issufficient that the urethra wall 002 does not bridge between adjacentturns of thread 103, but rather is only displaced in a manner closelyconforming to the cross section of thread 103, thereby providing thelongitudinal grip on urethra wall 002 for advancing and retracting thecatheter.

Referring to FIG. 1, catheter 101 is shown in proper position fordraining bladder 004, after it has been advanced through the urethra 006until the helix passes out of the urethra into the bladder.

It is apparent from the anatomy shown in FIG. 1, that thread 103 must belimited in length to be advanced to any point above the sphincter 008,so that the sphincter may contract directly onto the smooth, round,exterior of tube 102, thereby preventing leakage around the tube, andfurther constraining catheter 101 from migrating or being forced out ofthe urethra by pressure from urine in the bladder. It is furtherapparent from the figure that there is a limit to the length of thread103 on a catheter that can be advanced to a position above the sphincter008, not more than about six turns within the optimal range of threadpitch, and still fit within the bladder 004 without interference. Alimited length of thread 103 also localizes the area of pulling force tothe upper end of catheter 101, assuring that the trailing length of thecatheter is drawn, not pushed, through the passage.

Referring to FIGS. 5 and 6, threaded catheter 111 for females, similarto catheter 101 for males, is made up of tube 112 with thread 113,attachable to flow control device 114. Tube 112 is extruded frompolyurethane material, has an inside diameter of 0.063 inches, anoutside diameter 112d of 0.125 inches, and is approximately seven incheslong. The durometer as measured on the smooth, outside wall of the tubeis 85 shore a. Distal end 115 is closed off, it's tip rounded to auniform radius of about 0.06 inches. Proximal end 116 of tube 112 issimply cut off square and attached to flow control device 114. Tube 112is sufficiently strong such that when the majority of its length iscontained within the urethra, it will withstand and transmit torque asapplied by finger force at the lower end external of the urethra, to thethread or helix.

Referring to FIGS. 5 and 6, thread 113 of catheter 111 is formed from astrip of polyurethane material with a rectangular cross section of width113a of 0.05 inches and height 31b of 0.10 inches, attached to tube 112starting 0.2 inches from distal end 115 and extending four turns aroundtube 112 in a clockwise direction towards proximal end 116 at a uniformpitch 113c of 0.25 inches, resulting in a four-turn thread or helixabout one inch long.

It is readily apparent from FIGS. 5 and 6 that the thread height 113b ofcatheter 111 at 0.10 inches, is much greater than twenty percent (20%)of tube diameter 112d, at 0.125 inches. This relative thread height isnecessary in order to expand and penetrate the longitudinal folds of thefemale urethra sufficiently far to achieve a useful grip by the thread.

Similar to the description of threaded catheter 101, the diameter 113dof the helix formed by thread 113 is equal to two thread heights 113bplus the diameter 112d, or in this case 2 times 0.10 plus 0.125 orapproximately 0.33 inches. The circumference C of the helix formed bythread 113 is calculated as π (pi) times the thread diameter 113d, or inthis case 3.14 times 0.33 or approximately 1.0 inches. The ratio R ofthread pitch 113c, at 0.25 inches, to the circumference C, at 1.0inches, is again much less than 1 to 1, thereby improving the leverageof the thread for converting rotation into longitudinal pulling power ascompared to larger ratios.

The shoulders of thread 113 have a radius of 0.015 inches. Catheter 111may be constructed or fabricated by the same means as catheter 101.

Referring to FIG. 5, two side drainage ports 117, connecting to lumen118, are oval in shape, the major axis of the oval being parallel withthe axis of tube 112 and about 1.5 times the minor axis, which is aboutequal to the diameter of the lumen. The two sideports 117 are configured180 degrees apart radially, and spaced longitudinally to fit between theturns of the thread.

Referring to FIG. 5 and 6, the ends of thread 113 are tapered from zeroto full height in three-quarters turn of the helix, to facilitategentle, gradual displacement of urethra wall by the thread when catheteris rotated clockwise for advancement and counterclockwise forretraction. The difference between width 113a and pitch 113c issufficient that the urethra wall does not bridge between adjacent turns,but rather is displaced in a manner closely conforming to the profile ofthe thread, thereby providing the longitudinal grip on the urethra wallfor advancing and retracting the catheter, the same as catheter 101 ofFIGS. 2 and 3.

The optimal position for threaded catheter 111 for draining the bladderof a female subject is where it is advanced through the urethra untilthe thread passes out of the urethra into the bladder, similar to howcatheter 101 is illustrated in FIG. 1, but for females.

A detailed method of self-administration of the urethra with theappropriate respective threaded catheter 101 or 111, or other similarthreaded devices, is explained: The user assembles materials including asterile threaded catheter 101 or 111, a container for urine, soap andwater, if the catheter is not pre-lubricated then a water solublelubricant, a mirror (for females), and tissues. The user will then washthe hands and urethral opening with soap and water, squeeze out a smallamount of lubricant into clean tissue, dip the distal end tip of thecatheter into the lubricant, and manually engage the tip of the catheterinto the urethral opening, (the mirror may be helpful for females toassist in locating the opening).

The user will then gently push and turn the catheter in far enough toengage the thread about one full turn with the urethra, and gentlyrotate the tube of the catheter in the direction of the thread,preferably clockwise, to advance the catheter into the urethra untilurine appears in the tube. The user then pauses to drain the bladder,directing the urine into the container, then resumes rotation of thecatheter until it is no longer advanced by the rotation, indicating thatthe thread of the catheter has passed into the bladder and the catheteris in proper position.

The user then places a flow control device on the proximal end of thecatheter and empties the bladder periodically as required. The catheteris removed when appropriate using similar precautions for cleanlinessand containment, by rotating the catheter in a direction opposite thedirection of insertion, presumably counterclockwise.

Referring to FIGS. 7, 8 and 9, another embodiment contemplated by theclaims is illustrated by catheter 121, which is made up of tube 122 withthread 123 applied in the form of a helix, and utilizing flexible shaftstylet 131 as an insertion and retraction tool. Stylet 131 has grip 133at the proximal end, for turning. Tube 122 is configured withnon-rotational fitment 124 near distal end 125 so that stylet 131 can beinserted through proximal end 126, up through lumen 128 of tube 122, andtip 134 of stylet 131 be then engaged with fitment 124 in a manner thatallows rotation of grip 133 in one direction to rotate catheter 121 foradvancement into the urethra, and in the other direction for retraction.

The flexible shaft 132 of stylet 131 is sufficiently strong such thatwhen it is fully inserted into catheter 121, it will withstand andtransmit torque as applied by finger force at the proximal end knurledknob grip 133 external of the urethra, to the thread 123. Stylet 131 isremoved after catheter 121 is installed, and reinserted for retractingthe catheter when required.

Fitment 124 is an elongated collar with a multi-faceted interior wall,securely anchored within tube 122, and configured to receive in anon-rotational relationship tip 134. Tip 134 is configured with acorresponding elongated, multi-faceted exterior shape and rounded end,to readily enter fitment 124. Stylet tip 134 and fitment 124 can bealternatively configured and connected by various means to provide anon-sliding as well as non-rotational connection.

Referring to FIG. 10, 11 and 12, a threaded foley-type catheter 141 ofthe invention is made from polyurethane material. It has a flexible tube142 with an axial drainage lumen 148 running from a drainage port 149 toit's proximal end 146a, and a thread 143 applied to it's externalsurface near it's distal end 145 in the manner of threaded catheterspreviously described. Catheter 141 has a thin-walled inflatable elasticballoon 150 encasing the helical thread 143 and sealed to tube 142 aboveand below the thread 143. Drainage port 149 is located above or distallyfrom balloon 150. A smaller inflation lumen 151 within tube 142communicates between inflation port 152 within the envelope of balloon150 to the distal end 146b of the catheter. Lumens 148 and 151 areisolated from each other, as indicated by FIGS. 11 and 12.

Balloon 150, when uninflated, is normally contracted tightly abouthelical element 143 as illustrated in FIG. 12, and may be inflated as inFIG. 10 by injecting fluid through lumen 151 into the balloon cavity153. The flexible tube 142 is of sufficient torsional strength towithstand and transmit rotational finger force at the proximal end tothread 143.

DILATORS AND OCCLUDERS:

Referring now to FIGS. 13, 14 and 15, dilator 201 and occluders 211 and221 are similarly constructed by configuring the upper end 205 of aflexible shaft 202 with tapered bulb 204 near it's distal end, anddisposing thereon one or two sections of thread 203. These threads aresimilar to thread 103 on catheter 101 of FIGS. 2 and 3, wherein theheight of the thread is at least twenty percent (20%) of the diameter ofthe shaft 202, and the ratio of thread pitch to the circumference of thethread diameter at any given point on the bulb or shaft is less than oneto one (1/1). The ends of threads 203 are tapered for ease of advancingand retracting, again similar to the threaded catheter of FIGS. 2 and 3.

Dilator 201, of FIG. 13, is configured with multiple turns of thread 203extending over both ends of tapered bulb 204, and is used to dilate aconstricted passage by being rotatingly advanced and retracted throughthe obstructed area of the passage in the same fashion as the threadedcatheters of the invention.

Occluder 211, of FIG. 14, is configured with two sections of thread 203,leaving the midsection or bulbous portion of tapered bulb 204 smooth andround in order to provide a uniform occluding surface. This occluder isused to plug or constrict a passageway at an interior point; beingrotatingly advanced to and retracted from that point in the same fashionas the threaded catheters of the invention.

Occluder 221, of FIG. 15, is configured with two sections of thread 203,the lower or proximal end thread 203 being disposed on the shaft 202below the tapered bulb 204, leaving the lower tapered end of bulb 204smooth and round in order to provide a uniform occluding surface. Thisoccluder is used to plug a passageway at the interior end neck orentrance; being rotatingly advanced until the tapered bulb passesentirely through the passage while the lower thread remains engaged inthe passage, and being then rotatingly retracted to seat the taperedbulb against the neck of the passage. The occluder is then rotatinglyretracted when appropriate.

STENTS AND INTRAURETHRAL VALVE CATHETERS:

Referring now to FIGS. 16-18, a threaded urethral stent 301 made frompolyurethane material has a tube 302 with an external thread 303 ofuniform pitch. Thread 303 is similar to thread 103 on catheter 101 ofFIGS. 2 and 3, wherein the height of the thread is at least twentypercent (20%) of the diameter of the shaft 202, and the ratio of threadpitch to the circumference of the thread diameter is less than one toone (1/1). The ends of thread 303 are tapered for ease of advancing andretracting through a passage. There is an interior shoulder 304 at thedistal end 305 of the stent, and a bushing 307 of relatively hardermaterial with a tapered interior wall 308 extending from the bushing'sfull diameter at one end to a uniform hexagonal aperture 309, bushing307 being affixed within the proximal end 306 of the stent and orientedwith tapered wall 308 extending proximally from aperture 309. Coiledsidewall reinforcement member 310 is secured within the remaining lengthof stent 301 by bushing 307 and interior shoulder 304. Alternativeembodiments may have a section of the thread being tapered to a lesserheight or no height, to provide a "waist" for gripping by a muscularzone such as the prostate or sphincter. Also, reinforcement member 310could be configured or molded into the sidewall tube 302.

Referring now to FIGS. 19 and 20, stylet 331, similar to stylet 131 ofFIG. 7, has flexible shaft 332 with grip 333 at the proximal end forturning, and hardened hexagon tip 334 at the distal end which closelyfits into aperture 309 of stent 301 in a non-rotational manner foremplacement of the stent by the method of the invention. The flexibleshaft 332 of the stylet is sufficiently strong such that when tip 334 isinserted into aperture 309, the shaft will withstand and transmit torqueas applied by rotational finger force at grip 333 to thread 303.

Referring now to FIG. 21 and 22, threaded stent-follower 341 has aflexible tube 342, lumen 347 of which is sized to accept the readyinsertion of tip 334 and shaft 332 of stylet 331 of FIG. 19. Tube 342 isof sufficient torsional strength to accept and transmit rotationalfinger force at it's proximal end 346 to it's distal end 345. A thread343 of uniform pitch and not more than six turns is applied to theexternal surface of tube 342 near distal end 345. Thread 343 conforms tothe same twenty percent (20%) rule of thread height to tube diameter,and ratio of thread pitch to thread circumference of less than one toone (1/1), as thread 103 in FIGS. 2 and 3 as described above. The endsof thread 343 are tapered for ease of advancing and retracting.

Referring to FIG. 17 and FIG. 22, bushing 351 has a uniform hexagonalaperture 352 the same size as aperture 309 in bushing 307 of stent 301,and a tapered interior wall 353 extended from it's full diameter at it'sproximal end to aperture 352. Bushing 351 also has an external taperedtip 354 at it's distal end. Bushing 351 is affixed within the distal end345 of tube 342 with tip 354 protruding, such that the distal end 345 ofstent-follower 341 mates with a self-centering action with the proximalend of stent 301 when the two devices are brought into contact withapproximate axial alignment. When stent-follower 341 and stent 301 arethus mated, tip 334 of stylet 331 may be extended through aperture 352and into aperture 309, thereby locking stent 301 and stent-follower 341into a fixed rotational relationship. In this condition, the rotation ofthe proximal end of stylet 331 and stent-follower 341, causes theconcurrent rotation of stent 301, whether to rotatingly advance orretract the stent. Stylet 331 may be withdrawn and stent-follower 341rotatingly retracted, leaving stent 301 positioned at any useful pointwithin a passageway.

Referring now to FIG. 23, threaded intraurethral catheter 361, shown incross section, incorporates means for flow control. The catheter has atube 362 made from a section of extruded polyurethane tubing material,with thread 363 of uniform pitch and not more than six turns applied toit's external surface. Thread 363 conforms to the same twenty percent(20%) rule of thread height to tube diameter, and ratio of thread pitchto thread circumference of less than one to one (1/1), as thread 103 inFIGS. 2 and 3 as described above.

Alternative embodiments may have a section of the thread being taperedto a lesser height or no height, to provide a "waist" for gripping by amuscular zone such as the prostate or sphincter. Also, reinforcementmember 370 could be configured or molded into the sidewall tube 362.

There is an interior shoulder 364 at the distal end 365 of catheter 361,a bushing 367 of relatively harder material with a tapered interior wall368 extending from the bushing's full diameter at one end to a uniformhexagonal aperture 369, bushing 367 being affixed within the distal end366 of catheter 361 and oriented with tapered wall 368 extendingproximally.

A coiled sidewall reinforcement member 370 and a check ball 371 aresecured within the remaining length of catheter 361 by bushing 367 andinterior shoulder 364 so that coiled member 370 holds ball 371 incompression against the upper end of bushing 367 in the manner of acheck valve, which prevents outward flow through the lumen 372 of thestent. Coiled member 370 may be compressed by upward movement of ball371, thereby opening the check valve to flow.

Referring to FIGS. 19, 21, 23 and 24, alternate hexagonal tip 384 forstylet 331 has a slightly concave proximal end 385 and flutes 386. Whenused in conjunction with stent-follower 341 to actuate the check valveof catheter 361, tip 384 is be inserted through aperture 369 of catheter361 to push ball 371 upward against coil member 370, thereby opening thecheck valve function and permitting outward flow of fluid through flutes386 and aperture 369 into and through stent-follower 341.

SUPRAPUBIC:

Referring now to FIGS. and 25-29, the threaded suprapubic catheter 401of FIG. 25 and 26 is constructed with a flexible tube 402 with a lumen408 connecting axial ports at the proximal end and the distal end, andan external thread 403 of uniform pitch applied at it's distal end. Asdescribed for catheter 101 of FIG. 2 and 3, the ratio of thread pitch403c to the circumference of thread diameter 403d is much less than oneto one (1/1). Tube 402 is of sufficient torsional strength to accept andtransmit rotational finger force applied at the proximal end to thedistal end. The ends of 403 are tapered for ease of advancing andretracting the catheter through the abdomen and into the bladder wall.

Referring to FIGS. 26 and 27, relative thread height 403b, as apercentage of tube diameter 402d, is necessarily much greater than inthe case of catheter 101 of FIGS. 2 and 3; greater than fifty percent(50%). The suprapubic catheter is being advanced by the rotation ofthread 403 along an unlined path through the abdomen, and being anchoredagainst longitudinal displacement by the low pitch 403c of thread 403 asto it's circumference in a hole pierced into organ wall 031 that mustencompass tube 402 plus thread 403 passing through the plane of theorgan wall 031. This is distinguished from the longer gripping surfaceavailable in a lined passage way as is the case for catheter 101 of FIG.4.

Referring to FIG. 28, a method by which suprapubic catheter 401 isapplied is conventional to the extent that trocar 421 and cannula 422are used with ultrasound or fluoroscopy to create the path throughabdomen wall 021 into the bladder organ 031; trocar 421 is removed andtemporary guide wire 423 is then inserted through cannula 422, extendingfrom outside the abdomen wall 021 to inside the bladder organ 031.Cannula 422 is then withdrawn leaving guidewire 423 as a connecting pathextending from outside the body, passing through the abdominal wall 021,and into the bladder organ 031.

Suprapubic catheter 401 is then threaded through it's axial ports ontothe proximal end of guide wire 423, and gently started into the abdomenwall 021 with a rotating motion about one turn until thread 403 isfirmly engaged. The catheter is then rotatingly advanced along the guidewire through the unlined pathway in the same manner as other threadeddevices of the invention, until thread 403 penetrates the wall of organ031 about one full turn, as determined by ultrasound, fluoroscopy orequivalent means. The distal end of catheter 401 is secured in anon-rotatable fashion to abdomen wall 021 using conventional adhesivemeans or equivalent means, thereby locking thread 403 at the distal endof the catheter in position in the wall of organ 031. Guide wire 423 iswithdrawn. Threaded suprapubic catheter 401 is then available for use.

Referring to FIG. 29, radiopaque markers 411 embedded at select pointsdisplaced along the perimeter of thread 403 provide the capability forexternal detection and monitoring through fluoroscopy or other means oforientation and movement of the distal end of the catheter.

CAMERA INTRODUCER:

Referring to FIGS. 30 and 31A, threaded camera introducer catheter 500,suitable for an average size adult's colon, consists of a bulbous tip501 connecting to a soft, flexible tube 502 which is about 5 feet longwith a tube diameter 502d of one (1) inch. Lumen 508 extends from theinterior face of a window 511 on the distal end of tip 501, through tip501 and tube 502 to the proximal end of tube 502.

Referring to FIG. 31A, external thread 503 with uniform pitch 502c of 1inch begins at the edge of window 511, tapering from nothing to a heightof about 0.16 inches, extending around tip 501 and tapering there toabout 0.32 inches and continuing proximally for about 6 inches alongtube 502. Referring to FIG. 31B, thread height then tapers from a threadheight of 0.32 inches down to 0.16 inches and continues at this heightto the proximal end of tube 502.

An alternative embodiment of the introducer 500 may have a relativelydiminutive tip, but maintain an external thread of equal or greaterheight and total circumference. Another variation of introducer 500 mayhave thread 503 applied only to it's distal end, the thread terminatingafter a few turns, analogous to catheter 101 of FIG. 2.

It is readily apparent from the dimensions of FIGS. 31A and B that the0.32 inch thread height of thread 503 spanning about 6 inches at thedistal end of camera introducer 500 is greater than twenty percent (20%)of tube diameter 502d. A relative thread height in the range of 20percent or more of the camera introducer diameter size appropriate tothe subject's size, is necessary to expand and penetrate the walls ofthe colon to a sufficient depth to achieve a useful grip by the threadin accordance with the rotate to advance technology of the invention.The relatively lower thread height of the continuing thread is adequateto assist in the rotational advancement of the fill length of the devicewithout exerting undue forward pressure on the distal end. It also aidsin the easing of advancement over the full length of the introduceraround and through the bends in the colon.

It will be further apparent, consistent with the techniques, structureand methodology of the invention, that the thread pitch 502c, at oneinch, is much less than the overall circumference of thread 503, therebyproviding the necessary leverage to translate rotational effort at theproximal end to a forward force significantly greater than theperpendicular scrapping force against the wall of the colon. Simplevector analysis confirms this result.

Referring to FIG. 32, a camera assembly 520 consists of camera 521 withlight lens 522 and image lens 523, attached to a flexible, hollow,jointed spine 531. A cable harness 541 connected to camera 521, passesthrough spine 531, extending out the proximal end and connecting to thenecessary power, control and display equipment. Spine 531 is constructedof a chain of vertebrae 532, connected by universal joints which combineflexibility with torsional strength.

Referring to FIG. 33, camera assembly 520 is shown installed in cameraintroducer catheter 501, with camera 521 secured within tip 501 by setscrew 512, so that the camera views forward through the window. Thecamera assembly and catheter are combined here as a camera introducersystem.

Referring to FIG. 34, rotating container and dispensing system 550consists of drum 551 with axial opening 552 around which handle 553 isrotatably attached. Catheter 501 is rotatingly dispensed duringapplication by holding handle 553 and rotating drum 551 while catheter401 is being rotatingly advanced in the subject colon.

As will be realized, the invention is capable of other and differentembodiments, and its several details are capable of modifications invarious obvious respects, all without departing from the invention. Theobjects and advantages of the invention may be further realized andattained by means of the instrumentalities and combinations particularlypointed out in the appended claims. Accordingly, the drawings anddescription are to be regarded as illustrative in nature, and not asrestrictive.

I claim:
 1. A threaded introducer system for accessing a bodilypassageway, said introducer system comprising:a flexible tube having adistal end and a proximal end, a longitudinal axis extending betweensaid distal end and said proximal end, and a lumen extending from saiddistal end to said proximal end, said lumen being sized to receivevisualization apparatus for visualizing structures disposed adjacent tosaid distal end of said tube; apparatus for connecting visualizationapparatus received within said lumen to said tube; and an externalthread disposed over said distal end of said tube, said external threadhaving a sufficient structural integrity, and a sufficient surfaceprofile, such that when said tube is disposed in a bodily passageway,rotation of said tube about said longitudinal axis will result inlongitudinal motion of said tube along said bodily passageway.
 2. Thethreaded introducer system of claim 1, said thread disposed oversubstantially the full length of said tube.
 3. The threaded introducersystem of claim 1, said distal end of said tube incorporating a window,said lumen terminating at said window.
 4. The threaded introducer systemof claim 3, said visualization apparatus comprising a visual sensorattached to the distal end of a flexible hollow spine and a cableharness extending from said visual sensor through said spine and out theproximal end thereof, said visual sensor and said spine being insertableand securable within said lumen of said tube with said visual sensorconfigured to view through said window.
 5. The threaded introducersystem of claim 1, said thread having a thread height of at least onefifth (1/5) of the outside diameter of said tube and a thread pitch notgreater than the circumference of the helix formed by said thread. 6.The threaded introducer system of claim 5, said tube having sufficientstrength to translate rotational force at said proximal end to saiddistal end when said introducer is engaged in a bodily passageway. 7.The threaded introducer system of claim 1, further comprising means fortransmitting fluids into or out of said tract.
 8. The threadedintroducer system of claim 7, said external thread comprising a threadlumen.
 9. The threaded introducer system of claim 8, said externalthread being filled with a fluid.
 10. The threaded introducer system ofclaim 1, said tube being a gastrointestinal tract stent, said systemfurther comprising means for emplacing said stent in said tract.
 11. Athreaded introducer system according to claim 1 wherein saidvisualization apparatus comprises a camera head.
 12. A threadedintroducer system according to claim 11 wherein said visualizationsystem comprises a visual sensor other than a camera head.
 13. Athreaded introducer system according to claim 1 wherein said externalthread is formed by inflating a hollow structure with fluid.
 14. Athreaded introducer system according to claim 1 wherein said flexibletube is constructed so that said visualization apparatus may bewithdrawn from said lumen after said flexible tube is disposed in saidbodily passageway.
 15. A threaded introducer system according to claim 1wherein said flexible tube and said external thread are coated with anoperative agent.
 16. A threaded introducer system according to claim 1wherein at least one of said flexible tube and said external threadcomprises a radiopaque material.
 17. A threaded introducer system foraccessing the gastrointestinal tract, comprising a flexible cathetertube with a lumen extending from the distal end of said tube to theproximal end of said tube, and further comprising an external threaddisposed over said distal end of said tube;said distal end of said tubeincorporating a window, said lumen terminating at said window; saidsystem further comprising a visual sensor attached to the distal end ofa flexible hollow spine, a cable harness extending from said visualsensor through said spine and out the proximal end thereof, said visualsensor and said spine being insertable and securable within said lumenof said tube with said visual sensor configured to view through saidwindow; said system further comprising a drum with an axial openingaround which a handle is rotatably attached, said drum sized to holdsaid introducer system in a coiled configuration, said drum rotatinglydispensing said system through said axial opening while said handle isheld in a non-rotational grip.
 18. A method for introducing a medicaldevice into a gastrointestinal tract using a threaded introducer, saidintroducer comprising a flexible catheter tube with a lumen extendingfrom the distal end of said tube to the proximal end of said tube and anexternal thread disposed over said distal end, said method comprising inany order the steps of:advancing said threaded introducer through saidgastrointestinal tract by rotating said proximal end, and inserting saiddevice into said threaded introducer through said proximal end.
 19. Themethod for introducing a medical device into a gastrointestinal tract ofclaim 18, said medical device being a conventional endoscope.
 20. Themethod for introducing a medical device into a gastrointestinal tract ofclaim 18, said medical device being an ultrasound transducer.
 21. Themethod for introducing a medical device into a gastrointestinal tract ofclaim 18, said medical device being a video camera.
 22. The method forintroducing a medical device into a gastrointestinal tract of claim 18,said medical device being a surgical tool.
 23. The method forintroducing a medical device into a gastrointestinal tract of claim 18,said method further comprising the step of:emplacing a short section ofsaid tube within said tract.
 24. A visualization system for traversing abodily passageway, said system comprising:a flexible tube having adistal end and a proximal end, a longitudinal axis extending betweensaid distal end and said proximal end, and a lumen extending from saiddistal end to said proximal end; visualization apparatus received insaid lumen for visualizing structures disposed adjacent to said distalend of said tube; and an external thread disposed over said distal endof said tube, said external thread having a sufficient structuralintegrity, and a sufficient surface profile, such that when said tube isdisposed in a bodily passageway, rotation of said tube about saidlongitudinal axis will result in longitudinal motion of said tube alongsaid bodily passageway.